Auto merge of #136225 - fmease:rollup-fm7m744, r=fmease

Rollup of 7 pull requests

Successful merges:

 - #135625 ([cfg_match] Document the use of expressions.)
 - #135902 (Do not consider child bound assumptions for rigid alias)
 - #135943 (Rename `Piece::String` to `Piece::Lit`)
 - #136104 (Add mermaid graphs of NLL regions and SCCs to polonius MIR dump)
 - #136143 (Update books)
 - #136147 (ABI-required target features: warn when they are missing in base CPU)
 - #136164 (Refactor FnKind variant to hold &Fn)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_ast/src/mut_visit.rs

@@ -954,8 +954,14 @@ fn walk_coroutine_kind<T: MutVisitor>(vis: &mut T, coroutine_kind: &mut Coroutin
 
 fn walk_fn<T: MutVisitor>(vis: &mut T, kind: FnKind<'_>) {
     match kind {
-        FnKind::Fn(_ctxt, _ident, FnSig { header, decl, span }, _visibility, generics, body) => {
+        FnKind::Fn(
+            _ctxt,
+            _ident,
+            _vis,
+            Fn { defaultness, generics, body, sig: FnSig { header, decl, span } },
+        ) => {
             // Identifier and visibility are visited as a part of the item.
+            visit_defaultness(vis, defaultness);
             vis.visit_fn_header(header);
             vis.visit_generics(generics);
             vis.visit_fn_decl(decl);
@@ -1205,13 +1211,8 @@ impl WalkItemKind for ItemKind {
             ItemKind::Const(item) => {
                 visit_const_item(item, vis);
             }
-            ItemKind::Fn(box Fn { defaultness, generics, sig, body }) => {
-                visit_defaultness(vis, defaultness);
-                vis.visit_fn(
-                    FnKind::Fn(FnCtxt::Free, ident, sig, visibility, generics, body),
-                    span,
-                    id,
-                );
+            ItemKind::Fn(func) => {
+                vis.visit_fn(FnKind::Fn(FnCtxt::Free, ident, visibility, &mut *func), span, id);
             }
             ItemKind::Mod(safety, mod_kind) => {
                 visit_safety(vis, safety);
@@ -1329,10 +1330,9 @@ impl WalkItemKind for AssocItemKind {
             AssocItemKind::Const(item) => {
                 visit_const_item(item, visitor);
             }
-            AssocItemKind::Fn(box Fn { defaultness, generics, sig, body }) => {
-                visit_defaultness(visitor, defaultness);
+            AssocItemKind::Fn(func) => {
                 visitor.visit_fn(
-                    FnKind::Fn(FnCtxt::Assoc(ctxt), ident, sig, visibility, generics, body),
+                    FnKind::Fn(FnCtxt::Assoc(ctxt), ident, visibility, &mut *func),
                     span,
                     id,
                 );
@@ -1476,10 +1476,9 @@ impl WalkItemKind for ForeignItemKind {
                 visitor.visit_ty(ty);
                 visit_opt(expr, |expr| visitor.visit_expr(expr));
             }
-            ForeignItemKind::Fn(box Fn { defaultness, generics, sig, body }) => {
-                visit_defaultness(visitor, defaultness);
+            ForeignItemKind::Fn(func) => {
                 visitor.visit_fn(
-                    FnKind::Fn(FnCtxt::Foreign, ident, sig, visibility, generics, body),
+                    FnKind::Fn(FnCtxt::Foreign, ident, visibility, &mut *func),
                     span,
                     id,
                 );
@@ -1965,14 +1964,7 @@ impl<N: DummyAstNode, T: DummyAstNode> DummyAstNode for crate::ast_traits::AstNo
 #[derive(Debug)]
 pub enum FnKind<'a> {
     /// E.g., `fn foo()`, `fn foo(&self)`, or `extern "Abi" fn foo()`.
-    Fn(
-        FnCtxt,
-        &'a mut Ident,
-        &'a mut FnSig,
-        &'a mut Visibility,
-        &'a mut Generics,
-        &'a mut Option<P<Block>>,
-    ),
+    Fn(FnCtxt, &'a mut Ident, &'a mut Visibility, &'a mut Fn),
 
     /// E.g., `|x, y| body`.
     Closure(

compiler/rustc_ast/src/visit.rs

@@ -65,7 +65,7 @@ impl BoundKind {
 #[derive(Copy, Clone, Debug)]
 pub enum FnKind<'a> {
     /// E.g., `fn foo()`, `fn foo(&self)`, or `extern "Abi" fn foo()`.
-    Fn(FnCtxt, &'a Ident, &'a FnSig, &'a Visibility, &'a Generics, &'a Option<P<Block>>),
+    Fn(FnCtxt, &'a Ident, &'a Visibility, &'a Fn),
 
     /// E.g., `|x, y| body`.
     Closure(&'a ClosureBinder, &'a Option<CoroutineKind>, &'a FnDecl, &'a Expr),
@@ -74,7 +74,7 @@ pub enum FnKind<'a> {
 impl<'a> FnKind<'a> {
     pub fn header(&self) -> Option<&'a FnHeader> {
         match *self {
-            FnKind::Fn(_, _, sig, _, _, _) => Some(&sig.header),
+            FnKind::Fn(_, _, _, Fn { sig, .. }) => Some(&sig.header),
             FnKind::Closure(..) => None,
         }
     }
@@ -88,7 +88,7 @@ impl<'a> FnKind<'a> {
 
     pub fn decl(&self) -> &'a FnDecl {
         match self {
-            FnKind::Fn(_, _, sig, _, _, _) => &sig.decl,
+            FnKind::Fn(_, _, _, Fn { sig, .. }) => &sig.decl,
             FnKind::Closure(_, _, decl, _) => decl,
         }
     }
@@ -374,8 +374,8 @@ impl WalkItemKind for ItemKind {
                 try_visit!(visitor.visit_ty(ty));
                 visit_opt!(visitor, visit_expr, expr);
             }
-            ItemKind::Fn(box Fn { defaultness: _, generics, sig, body }) => {
-                let kind = FnKind::Fn(FnCtxt::Free, ident, sig, vis, generics, body);
+            ItemKind::Fn(func) => {
+                let kind = FnKind::Fn(FnCtxt::Free, ident, vis, &*func);
                 try_visit!(visitor.visit_fn(kind, span, id));
             }
             ItemKind::Mod(_unsafety, mod_kind) => match mod_kind {
@@ -715,8 +715,8 @@ impl WalkItemKind for ForeignItemKind {
                 try_visit!(visitor.visit_ty(ty));
                 visit_opt!(visitor, visit_expr, expr);
             }
-            ForeignItemKind::Fn(box Fn { defaultness: _, generics, sig, body }) => {
-                let kind = FnKind::Fn(FnCtxt::Foreign, ident, sig, vis, generics, body);
+            ForeignItemKind::Fn(func) => {
+                let kind = FnKind::Fn(FnCtxt::Foreign, ident, vis, &*func);
                 try_visit!(visitor.visit_fn(kind, span, id));
             }
             ForeignItemKind::TyAlias(box TyAlias {
@@ -858,7 +858,12 @@ pub fn walk_fn_decl<'a, V: Visitor<'a>>(
 
 pub fn walk_fn<'a, V: Visitor<'a>>(visitor: &mut V, kind: FnKind<'a>) -> V::Result {
     match kind {
-        FnKind::Fn(_ctxt, _ident, FnSig { header, decl, span: _ }, _vis, generics, body) => {
+        FnKind::Fn(
+            _ctxt,
+            _ident,
+            _vis,
+            Fn { defaultness: _, sig: FnSig { header, decl, span: _ }, generics, body },
+        ) => {
             // Identifier and visibility are visited as a part of the item.
             try_visit!(visitor.visit_fn_header(header));
             try_visit!(visitor.visit_generics(generics));
@@ -892,8 +897,8 @@ impl WalkItemKind for AssocItemKind {
                 try_visit!(visitor.visit_ty(ty));
                 visit_opt!(visitor, visit_expr, expr);
             }
-            AssocItemKind::Fn(box Fn { defaultness: _, generics, sig, body }) => {
-                let kind = FnKind::Fn(FnCtxt::Assoc(ctxt), ident, sig, vis, generics, body);
+            AssocItemKind::Fn(func) => {
+                let kind = FnKind::Fn(FnCtxt::Assoc(ctxt), ident, vis, &*func);
                 try_visit!(visitor.visit_fn(kind, span, id));
             }
             AssocItemKind::Type(box TyAlias {